Anodize, plating and powder coat on machined aluminum parts. We machine to ±0.005 mm, control coating buildup, and mask what must stay conductive.
Most coating failures are decided before the part ever enters the tank. These are the ones we see repeatedly.
Anodize grows the surface. A 25 μm hardcoat layer adds roughly 25 μm per side, so a Ø6 H7 bore shrinks to about Ø5.95 mm. The pin will not enter. This is a drawing problem, not a tank problem: the shop has to offset the bore before machining or mask it during anodize.
Alloy chemistry drives dye response. 6061 and 6063 take black evenly. 7075 and 2024 go bronze or muddy brown in the same bath, because of copper and zinc content. If the drawing calls for black on 7075, either accept the colour shift or switch the alloy.
The oxide layer is porous by nature. Fingerprints, coolant residue and cutting oil wick into open pores and stay there. Parts that travel through a second machining step or a wash line need sealing unless the finish callout says otherwise.
Anodized aluminum is an insulator. A chassis that needs to bond to a PCB ground plane through its mounting face will read open circuit once the whole part is coated. That face needs masking, or a conductive finish instead.
Coating is a dimensional feature. We treat it like one.
Chromic anodize builds the thinnest layer. It is the right call for tight-tolerance parts and for assemblies where fatigue life matters, because the thin film cracks less under load.
Sulfuric anodize is the general-purpose choice: cosmetic covers, enclosures, brackets. Hardcoat anodize gives a dense, wear-resistant surface for sliding contacts and wear plates, but the layer is thick enough to move dimensions, so bores and threads need planning.
Electroless nickel goes on evenly, including inside bores and on complex geometry, and it stays conductive. For RF housings and parts that need solderability, that combination beats anodize outright.
Powder coating covers more area per dollar on large enclosures and gives colour without a dye bath. Black oxide is a thin conversion layer for tooling and fixtures where appearance matters less than corrosion resistance.
Thickness figures are typical ranges for machined aluminum parts.
| Coating | Typical thickness | Best for | Watch out for |
|---|---|---|---|
| Chromic anodize | 0.5–8 μm | Tight tolerances, fatigue-critical | Limited colour range |
| Sulfuric anodize | 2–25 μm | Covers, enclosures, brackets | Porous until sealed |
| Hardcoat anodize | 13–115 μm | Wear plates, sliding surfaces | Moves bore and thread sizes |
| Electroless nickel | 5–25 μm | Ground paths, solderable faces | Not for cosmetic black |
| Powder coat | 50–100 μm | Large frames and enclosures | Thick buildup at edges |
| Black oxide | 1–3 μm | Fixtures, tooling, jigs | Minimal corrosion protection |
Aluminum parts move from machine to finish without a broker in between.
Sixteen simultaneous 5-axis centers cut contoured aluminum housings, impellers and brackets in one setup, so coating-critical faces stay aligned.
Milling and mill-turn centers handle prismatic and round aluminum parts, including the thread and bore offsets that anodize will consume.
Formed aluminum enclosures and chassis, ready for powder coat or anodize, with bend radii set for the coating thickness.
ADC12 and aluminum alloy castings for larger housings, finished to the same surface specification as machined parts.
Anodizing, electroless nickel, zinc, silver and gold plating, powder coating, black oxide, blasting, brushing and laser marking.
Single prototypes through production runs of 10,000+ parts, with no minimum order quantity on either end.
Figures apply to aluminum and mixed-alloy work.
| Item | Range |
|---|---|
| Maximum part size | 4,000 mm |
| Machining tolerance | ±0.005 mm (±0.0002 in) |
| As-machined finish | Ra 1.6–3.2 μm |
| Fine finish | Ra 0.2–0.8 μm |
| Laser marking | 1.5 mm minimum character height |
| Order quantity | One prototype to 10,000+ parts |
Fifteen years quoting anodize and plating on machined aluminum, including the masking and offset work that keeps assemblies fitting.
Sixteen simultaneous 5-axis centers, twelve four-axis mills, twenty-seven three-axis machines and sixteen mill-turn centers.
Held on coating-critical features so the anodize layer lands where the drawing expects it, not where the tank decides.
Raw material check, in-process monitoring and final inspection. Reports available on request.
Quotation and free DFM analysis within twelve hours. Production can start within twenty-four hours.
No minimum order quantity. One prototype part and a 10,000-piece run go through the same process control.
Black anodize with masked mounting faces. The requirement is a matte, non-reflective surface that still passes a ground continuity check.
Hardcoat on wear faces, clear anodize elsewhere. Sealing and salt-spray expectations come from the vehicle program, not from us.
Powder coated enclosure with an electroless nickel grounding boss. Large flat panels stay within flatness after the bake.
The oxide grows into the aluminum and out of it at roughly the same rate, so a 25 μm layer adds about 12 to 13 μm per side above the original surface, and the same below it.
For a bore, plan on roughly 25 μm of diameter loss. If the fit is H7, we offset the bore in the program or mask it, and we tell you which before the part is cut.
Mask them if the fastener must run freely to the bottom of the thread, or if the thread carries current. Anodized threads gall and change pitch diameter.
For threads that are only lightly loaded and never disassembled, leaving them coated is usually fine and cheaper.
No. Copper and zinc in 7075 shift the dye response toward bronze or brown in a standard black bath.
If the colour must match across a mixed 6061 and 7075 assembly, either use a dye system qualified for both alloys or keep the visible parts on 6061.
Sealing closes the pores and stops staining, finger marks and coolant residue from soaking in. It also reduces the dye bleed that shows up on humid days.
Skip it only when the drawing calls for an unsealed surface, typically when the part will be bonded or painted afterward and the shop needs a keyable surface.
Yes, with masking. We cover the contact faces before anodize so the oxide never forms there, then leave those faces bare or plate them with electroless nickel.
The alternative is to skip anodize entirely and use electroless nickel across the whole part, which is conductive everywhere.
Ra 0.8–1.6 μm is a sensible default for cosmetic anodized aluminum. It hides tool marks and takes dye evenly.
A mirror polish before anodize shows every scratch and is not worth the cost unless the part is a visible trim piece.
We can, but we inspect incoming parts first. Castings with porosity, or parts with unknown alloy, often fail in the tank and the cost is already sunk.
When the alloy is unknown, we run a small test coupon before committing the batch.
Send the 3D model and a 2D drawing with the finish callout, including any masking notes. Quotation and DFM feedback come back within twelve hours.
If the finish is undecided, say what the part has to survive and we will propose a coating and note the trade-offs.
Upload your model and we will return a quote with the coating, thickness and masking plan within 12 hours.
12-hour quote100% inspectionNo minimum orderNDA on request
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Upload your 3D model or 2D drawing and get a quotation with a free DFM analysis. Maximum processing size 4,000 mm.
CNC Metals 13 grades
CNC Plastics 10 grades
Machines & processes 12 options
Surface & post-processing 10 options
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